The present invention relates to an image display device; and, more particularly, the invention relates to an image display device which produces a display by making use of the rotation of electronic balls.
In providing a thin image display device, there has been extensive development of liquid crystal display devices. However, with respect to liquid crystal display devices, there still remains the drawback that it is difficult to hold the same image for a long period of time. Recently, as a novel image display device which can solve this drawback, a system has been proposed in which a display is generated using rotatable electronic balls.
To briefly explain this method, two hemispheres of the same ball are respectively coated in black and white to form a black region and a white region, and static electricity having either a plus polarity or a negative polarity is preliminarily imparted to the black region, for example. Then, this ball is held between electrodes which are formed on upper and lower substrates. In applying an electric field between the upper and lower electrodes, when the intensity of the electric field is less than a threshold value, the black region is directed toward the display side, so that a black display is obtained; while, when the intensity of the electric field is equal to or greater than the threshold value, the ball is rotated and the white region is directed toward the display side, so that a white display is obtained, whereby a black-or-white binary display is produced. The method including electrophoresis can hold the same image for a long time, and, hence, the application of this method to a so-called electronic paper is being developed.